研究者詳細 - 玉川　雅章

口頭発表・ポスター発表等 - 玉川　雅章

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末梢静脈血管内カテーテルまわりの流れの数値解析と血栓形成

山口泰申, 宮村裕子, 玉川雅章

流体工学部門講演会講演論文集

開催期間： 2018年01月記述言語：日本語

Catheter is commonly used medical equipment inserted into the small peripheral intravenous (PIV) for infusing fluids, drug and transfusions. In case of the treatment, thrombus formation sometimes occurs at the catheter outlet. The reasons are considered to be infants' crying and motion of catheter. In this investigation, effects of the catheter position, venous flow and catheter flow on the thrombus formation are examined in the CFD model composed of the catheter and vein. By using the result, the probability of thrombus formation is evaluated as the product of strain rate and residence time near the wall. It was found that there is high probability area of thrombus formation near the catheter outlet.

CiNii Article

各種サイトカイン濃度勾配による好中球の水中推進機構の解明

田端純風, 玉川雅章

バイオフロンティア講演会講演論文集

衝撃波培養組織再生システム開発のための時短パルスレーザー誘起衝撃波生成の基礎的検討

寺島涼介, 今門利和, 玉川雅章

年次大会

開催期間： 2018年01月記述言語：英語

This paper proposes a culture tissues regeneration system combining culture promotion and capsule destruction by shock wave, and describes the development of the system. In this system, shock wave are applied to microcapsules containing bubbles for DDS to simultaneously stimulate cells and destroy capsules. The capsule have an important role as a medium for cell culture in regenerative medicine. In this study, shock wave is generated in water using short-time laser with femtosecond as the purpose of stimulating cells. Particle motion around the focal point was observed by image processing. And the pressure at the focal area was also obtained by solving motion equation of particle. As a result, the pressure received by the particle at the position of 48.9μm from the focal point was 192Pa, and the pressure in the focal area was predicted to be 0.29MPa.

CiNii Article

弁周囲逆流モデルでのせん断流れによる血栓形成の可視化とその解析

山口翔史, 山畳悠司, 玉川雅章

年次大会

開催期間： 2018年01月記述言語：日本語

TAVI (Transcatheter Aortic Valve Implantation) is a minimally invasive treatment for Aortic Stenosis. Although when PVL (Paravalvular Leaks) occurred after surgery, life prognosis worsens. In this research, we made a PVL model with clearance around the orifice and compare visualization of thrombus formation on PVL flow visualized by optical system and flow field is also analyzed by CFD. Experimental result showed that PVL model thrombus formation depend on the clearance size. That is, thrombus formation in large leak model start around the leakage, whereas thrombus formation in small leak model start around the orifice. According to the CFD result, it was found that vortex and contraction existed in the flow field. It turned out that the vortex became smaller as the leakage became larger, but the contraction flow became larger as the leakage increased. Next, the difference in thrombus formation rate (Rs) near the wall compared with the clearance size. As a result, it was found that the leakage is large, the Rs increase. It was suggested that small wake by large leakage flow affected thrombus formation.

CiNii Article

衝撃波組織再生培養システム開発のための時短パルスレーザー誘起衝撃波生成について

今門利和, 玉川雅章

年次大会

開催期間： 2017年09月記述言語：日本語

This paper describes development of regenerative medical system using microcapsules including gas by shock waves. The newly proposed system has two features. One is culture mode by pressure wave, and the other is rupture mode by interactions between shock waves and bubbles in microcapsules. Especially, the worked shock waves by using short-time laser with femto seconds will be generated in the water in this investigation. It was found that the optical system was established correctly by checking laser power. The control of power, duration and waves were discussed to improve the pressure waves in water. The result showed that (1) optical system was established by confirming maximum pressure at the focal point, (2) maximum pressure is 0.36MPa, and the pressure decays with distance from the focal point.

CiNii Article

大動脈内人工弁周りの流れの解析と血栓について

山畳悠司, 玉川雅章, Bazri Adi Bin, Ahmad Kamarul Bin, 平山千春, Yi Yingming

年次大会

開催期間： 2017年09月記述言語：日本語

TAVI (Transcatheter Aortic Valve Implanation) is one of treatments for Aortic Stenosis.Although TAVI has been established as a treatment less burdensome to patients, there is the fact that when PVL (Paravalver Leaks) occurs after surgery, life prognosis worsens. In the CFD simulation, it is shown that when a prosthetic valve smaller than the aortic inner diameter is placed, PVL is generated, which greatly affects mass flow loss and blood flow recirculation, causing thrombosis and aortic wall deformity . However, experiments using actual artificial valves have not yet been carried out satisfactorily. In this study, as a first step to investigate the cause of PVL, a prosthetic valve was placed in a simple cylinder tube, so that PVL does not occur, and analyze the flow around the prosthetic valve. We used the PIV system in the experiment. By this experiment, when the prosthetic valve is indwelled so as not to have a gap with the wall surface, it is understood that flow stagnation is occurring at the posterior part of the prosthetic valve, and it is considered that stagnation of this flow can cause thrombus formation. Through this experiment, We found the characteristics of the flow behind the prosthetic valve, and it became a foothold for clarification of PVL.

CiNii Article

濃度輸送と凝集を考慮したCFDによるせん断流れ場での血栓予測法について

玉川雅章, イインミン, 山畳悠司

生体医工学

開催期間： 2017年01月記述言語：日本語

本研究では，濃度輸送を考慮したFDM法と凝集を考慮したDPD法の統合した方法を提案するものである．計算対象は，これまでに血栓の可視化を行ったオリフィス形状であり，計算は流れ場を用いて，化学種の濃度場を輸送方程式から計算する．これとDPD法を凝集の部分に適用し，結びつけることを行う．このDPDを導入することで凝集した活性化した血小板の数を評価できた．壁面での付着を確率を用いることで，壁面での凝集した活性化された血小板の数も得ることができた．これらの数とこれまでの実験の血栓生成率との比較を行った．

CiNii Article

CFD による各種せん断流れにおける溶血評価について

平山千春, 玉川雅章, 堀江昌朗, 赤松映明

バイオエンジニアリング講演会講演論文集

せん断流れの壁面血栓形成予測のための血小板輸送のCFD解析

Yi Yingming, 平山千春, 中田祥平, 玉川雅章

バイオエンジニアリング講演会講演論文集

円管内オリフィスならびにノズルまわりのせん断流れにおける血栓形成の予測について

中田祥平, 宮村裕子, 平山千春, Yingming YI, 玉川雅章

バイオフロンティア講演会講演論文集

各種濃度条件における好中球の濃度勾配による水中推進機構の解明

伊藤誠, 玉川雅章, 廣瀬智也

バイオエンジニアリング講演会講演論文集

せん断流れにおける血栓形成の可視化とその輸送方程式を用いた数値シミュレーション

玉川雅章, イインミン, 平山千春, シウエウウエイ

生体医工学

開催期間： 2016年01月記述言語：日本語

This paper describes the visualization of thrombus formation on shear flows such as orifice flow and Cuette flow, and development of numerical simulation for predicting thrombus formation by transport equation. Using the transparent devices, the thrombus formation on the wall on shear flow is observed and obtained the rate of thrombus formation by image processing. The results showed that the thrombus rate is increasing with shear rate by changing geometries of orifice and rotational speed of Cuette flow. On the other hand, the prediction method using CFD including transport equation of species using modified shear dependent model in orifice flow and Cuette flow is developed. In this computation, activated platelet is evaluated. The results show that deposition rate of activated platelet is increasing with shear rate.

CiNii Article

衝撃波を利用した培養組織再生システムの開発のための気泡内包マイクロカプセルの設計について

小笠原僚, 玉川雅章, 江副佑樹

年次大会

せん断流れにおける壁面での血栓形成の方向性について

平山千春, 玉川雅章, Yi Yingming

バイオフロンティア講演会講演論文集

せん断流れの壁面血栓形成予測のための濃度輸送による CFD 解析

中田祥平, イインミン, 玉川雅章

流体工学部門講演会講演論文集

開催期間： 2016年01月記述言語：日本語

This paper describes the analysis of platelet aggregation on orifice flow by dissipative particle dynamics (DPD). DPD is a computational method for simulating platelet aggregation. In this paper, the DPD method is used for predicting platelet aggregation on orifice flow with concentration transport, and the sensitivities of the configuration and parameters on model are discussed. From computational results, it is found that effects of orifice configuration and parameter of interaction force on platelet aggregation are large compared with other factors. It is expected that the DPD will be combined with transport equation of concentration for accurate prediction of thrombus formation with aggregation.

CiNii Article

サイトカイン濃度勾配による好中球の水中推進機構の解明

廣瀬智也, 玉川雅章

年次大会

開催期間： 2016年01月記述言語：日本語

Neutrophil is known as one of the immunological system, and it has chemotaxis by concentration gradient of cytokine. In general, the neutrophil is moved to high concentration of cytokine in the blood vessel, and derived to the inflammation areas. However, the mechanism of propulsion has not been elucidated yet. By understanding this mechanism, it can be applied to medical technologies such as drug delivery systems and micro machines. Therefore, it is necessary to elucidate the principle of neutrophil's propulsion. In our previous investigation, it was found that concentration gradient on the surface of neutrophil is reverse toward surrounding fluid. In this paper, detailed concentration distribution and concentration gradient on the neutrophil's membrane are examined by experimental. From the result, It was found that concentration gradient occurred by the decreasing of concentration at the neutrophil's membrane of cytokine insert side.

CiNii Article

一様せん断流れ場における壁面付着血栓形成の観察とその機構

山畳悠司, 玉川雅章, シウエイウエイ

年次大会

免疫機構における濃度勾配による好中球の水中運動について

廣瀬智也, 玉川雅章, 伊藤誠

流体工学部門講演会講演論文集

開催期間： 2016年01月記述言語：日本語

Neutrophil is known as one of the immunological system, and it has chemotaxis by concentration gradient of cytokine. In general, the neutrophil is moved to high concentration of cytokine in the blood vessel, and derived to the inflammation areas. However, the mechanism of propulsion has not been elucidated yet. By understanding this mechanism, it can be applied to medical technologies such as drug delivery systems and micro machines. Therefore, it is necessary to elucidate the principle of neutrophil's propulsion. In our previous investigation, it was found that concentration gradient on the surface of neutrophil is reverse toward surrounding fluid. In this paper, detailed concentration distribution and concentration gradient on the neutrophil's membrane are examined by experimental. From the result, it was found that velocity of neutrophil's motion was changed by concentration gradient on the membrane.

CiNii Article

濃度輸送方程式を考慮した壁面上白色血栓形成予測のための数値シミュレーション

Yi Yingming, 玉川雅章, 平山千春

年次大会

衝撃波を利用した培養組織再生システムの開発のためのカプセル内気包変形挙動解析

江副佑樹

日本機械学会 2015年度年次大会日本機械学会

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口頭発表・ポスター発表等 - 玉川 雅章

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口頭発表・ポスター発表等 - 玉川　雅章